Dresser for grinding or lapping tool



A.-K-. SELNE S DRESSER FOR GRINDING OR LAPPING TOOL Dec. 24, 1957 2 Sheets-Sheet 1 Filed Jan. 11, 1955 INVENTOR. ALF K5ELNE H \S ATTORNEY Dec. 24, 1957 A. K. SELNES DRESSER FOR GRINDING 0R LAPPING TOOL 2 Sheets-Sheet 2 Filed Jan. 11, 1955 INVENTOR;

ALF .K. \SELIVES BY HIS H TDR/Vfy DRESSER FOR GRINDING R LAPPING TOOL 'Alf K..Selnes, Detroit, Mich. Application January 11, 1 955, SerialNo. 481,183

Claims. (Cl..125--11) This invention relates to a dresser for a =grindingor lappingstone used in finishing work centers and for dressing the lapping tool between lapping operations without removal of the tool from a rotary spindle such as for instance a drill press.

It is an object of the present invention to provide a swingable support for the dressing tool which can be swung into and out of dressing position and which rides on a cone carried by the rotatable spindle.

Another object of the invention is to provide a resilient support for the lower dead center work rest which provides a cushion for the work so that the fine point of the lapping tool is not broken off.

A further object of the invention is to provide a swingable table support, about the axis of the main support,

having a guide at one side of the table support for riding on an offset rod which is parallel to the main support, so as to position the table and work directly in axial alignment with the axis of the dressing tool.

Other objects and advantages of the invention will more fully appear from the following description taken in connection with the accompanying drawings in which;

Fig. 1 is a side elevational view of a machineembodying the features of myimproved device;

Fig. 2 is a cross sectional view of the machine taken on line 22 of Fig. 1;

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. l; and

Fig. 4 is a cross sectional w'ew showing-a modified form of the lower work rest.

Referring to the drawings, I have shown the invention applied to a machine of the drill press type having a base 10, a vertical column 12 and a head 14. The head 14 is provided with a back plate 16 adjustably supported on rods 18 mounted in bosses 20 at each side of the head 14. A- driving motor 22 is secured to the plate 16. The motor 22 carries stepped pulleys 24 and a driving shaft 26. A belt 28 forms the drive between the pulleys 24 and a similar set of pulleys which are reversely arranged in the forward extension of the head 14 in which is mounted the rotatable spindle 30 carrying the grinding or lapping stone 32 in a chuck 34. The rotatable spindle is advanced toward or retracted from the work by a manually operable handle 36.

A split collar 38 is vertically adjusted on the column 12 and carries a forwardly extending table 40 upon which the lower work support 42 is carried. The table 40 is provided with a rearwardly extending arm 44, at one side of the table. The outer end of the arm 44 is provided with a roller 46 which rides on the outer periphery of a shaft 48 supported by collars 50 and 52 on the main column 12. The shaft 48 is spaced from and to one side of the main column 12. This arrangement provides a limit stop for the arcuate movement of the table 40 on the column 12 so that the axis of the work support 42 can be brought into axial alignment with the axis of the lapping stone 32. The arm 46 is longitudinally adatent justable on the table 40 by headed bolts 54 screwthreaded 'to the tableim slots 56.

It is desired to have a limited degree of cushion affect for the lower work support 42. As shown in Fig. 3 a cylindrical pin 42, having a reduced diameter portion 58 is axiallymovabl'e in a bearing 60 which is secured to the table 40 by :screws 62. A coil compression spring 64 surrounds the reducedportion of the pin 42 and abuts between theshoulder66 and a washer 68 secured to the bottom of the bearing 60. Thereduced portion of the pin 42 is threaded at its outer end and freely passes through the washer 68. A nut 70 adjusts the compression of the spring 64 and limits the upward-movement of the pin '42 within the bearing 60. The spring64 offers a cushionsupportfor the pin 42.

A boot 72, preferably leather, embraces the outer periphery of the pin 42 and the bushing 60 with the usual garter springs 74 and 76, retains lubricant in the hearing 60 so-that the pin 42 is freely slidable therein. This boot also se'r'vesto prevent grinding dirt and grit from entering the bearing.

A modifie'd'form of the cushion device is shown in Fig. 4 wherein the reduced portion of the pin is cut off and the'pin42' seats on a rubber pad 78.

The grinding or lapping stone 32 is illustrated as one for forming conical work centers and is provided with a pointed end 80, the included angle shown as sixty degrees. The stone 32 is held on the rotating spindle 30 by thechuck 34 and the spindle is adapted for reciprocation toward'and away from the pin 42. The tapered surface requires reshaping, due to Wear, and the angle of the taper must be maintained to the predetermined degree.

Above the stone 32 and rotatable with the spindle30, I have provided a conical sleeve 82 having a conical outer periphery, the angle of which corresponds to the desired angle of the stone 32, here shown as having an included angle of sixty degrees. The conical sleeve 82 is held on the spindle 30 by collars 84 at the opposite ends of the sleeve.

The conical sleeve 82 has a central opening therethrough which fits over the free end of the spindle 30. The spindle 30 is threaded and the chuck 34, which is threaded on the spindle 30, urges the sleeve into locked position with the spindle.

A support 86 is carried by the column 12 and an arm 88 is pivoted by a screw 90 for swinging movement on the support 86. The outer end of the arm is provided with a block 92 and is adjustably secured to the opposite end of the arm 88 by a screw 94. At one side of the screw 94 and arranged transversely in the block 92 is an adjustable follower 96 which is in contact with the outer'periphery of the conical sleeve 82, when the arm 88 is swung toward the axis of the spindle 30. At the other side of the screw 94 is a tool dresser 98 preferably in the form of a cutting diamond. The block 92 is positioned on an angle corresponding to the angle of the stone cutting face. The diamond cutting surface 98 is brought into contact with the cutting face of the stone 32 and the follower 96 is adjusted to contact the outer conical surface of the sleeve 82.

In the operation of the device above described, the arm 88 and block 92 are normally swung about the pivot of the screw 20 to one side out of the path of the stone. The operator is free to lower the rotating stone 32 toward the work to grind or lap the tapered center. When the cutting surface of the stone requires sharpening or repointing, the arm 88 and block 92 are swung toward the axis of the spindle 30. The follower 96 contacts the outer surface of the conical sleeve 82, and by reciprocation of the spindle and stone, the arm is moved toward and away from the axis of the spindle. The follower correctly positions the diamond cutter 98 with respect to the stone 32. As the stone 32 and sleeve 82 are raised and lowered by the operator, the conical surface of the sleeve 32 moves the block 92 and arm 88 toward and away from the axis of the spindle and the diamond cutter follows a true path determined by the conical sleeve 82.

I have herein shown and described a preferred embodiment of the invention, but it will be understood that various changes including the size, shape and arrangement of parts may be made without departing from the invention, and it is my intention to cover by the appended claims such changes as may be reasonably made.

I claim:

1. In a machine of the class described comprising, a supporting column, a rotatable spindle having its axis radially spaced from said supporting column, means for reciprocating said spindle, a lapping tool carried at the outer end of said rotatable spindle, the working face of said tool having a predetermined outer peripherial contour, a member carried by said spindle axially spaced from said tool and having an outer peripherial contour corresponding to the predetermined contour of said tool, an arm pivotally mounted on said column, a block secured to the free end of said arm, a follower carried by said block for contact engagement with the outer periph cry of said member when said arm is swung toward the axis of said spindle, and a dresser tool carried by said block for contact engagement with said lapping tool when said arm is swung toward the axis of said spindle.

2. In a machine of the class described comprising, a supporting column, a rotatable spindle having its axis radially spaced from said supporting column, means for reciprocating said spindle, a collar vertically and rotatably adjustable on said column, a table having a supporting surface below said spindle carried by said collar and having vertical and angular movements with respect to said column, a rod parallel to said column and having its axis spaced therefrom, a longitudinally adjustable bar carried by said table extending toward said rod, and a roller at the outer free end of said bar for rolling contact engagement with said rod for limiting the angular position of said table and for guiding said table in its vertical and angular movements.

3. A machine of the class described comprising, a base, a vertical column carried by said base, a collar adjustable axially on said column, a motor carried by said collar at one side thereof and a rotatable spindle driven by said motor carried by said collar at the opposite side thereof and having its axis spaced from said column, means for reciprocating said spindle axially, a lapping tool carried by said spindle, a member carried by said spindle axially spaced from said lapping tool, the outer periphery of said member having a predetermined contour equivalent to the desired peripherial contour of the working face of said lapping tool, a swingable arm having one end pivotally supported by said column, the outer free end of said arm having a follower and a dressing tool for contact engagement with the outer periphery of said member and said dressing tool respectively when swung toward the axis of said spindle.

4. A machine of the class described comprising, a base, a vertical column carried by said base, a first collar adjustable axially on said column, a motor carried by said collar at one side thereof and a rotatable spindle driven by said motor carried by said collar at the opposite side thereof and having its axis spaced from said column, means for reciprocating said spindle axially, a lapping tool carried by said spindle, a member carried by said spindle axially spaced from said lapping tool, the outer periphery of said member having a predetermined contour equivalent to the desired peripherial contour of the working face of said lapping tool, a swingable arm having one end pivotally supported by said column, the outer free end of said arm having a follower and a dressing tool for contact engagement with the outer periphery of said member and said dressing tool respectively when swung toward the axis of said spindle, a second collar adjustable axially on said column, a table carried by said second collar beneath said spindle, a rod parallel to said, column and spaced therefrom, a bar adjustably secured to said table for limiting the angular position of said table and second collar by contact engagement with said rod, and an axially yieldable dead center carried by said table.

5. A machine of the class described comprising, a base, a vertical column carried by said base, a collar adjustable axially on said column, a rotatable spindle carried by said collar and having its axis spaced from said column, means for rotating said spindle, means for recip rocating said spindle axially, a lapping tool carried by said spindle, amember carried by said spindle axially spaced from said lapping tool, the outer periphery of said member having a predetermined contour equivalent to the desired peripherial contour of the working face of said lapping tool, a swingable arm having one end pivotally' supported by said column, the outer free end of said arm having a follower and a dressing tool for contact engagement with the outer periphery of said member and said dressing tool respectively when swung toward the axis of said spindle.

References Cited in the file of this patent UNITED STATES PATENTS 

